1. Technical Field
This invention generally relates to pocket screwdrivers, and more particularly, to pocket screwdrivers having a plurality of tool bits and means for increasing applied torque.
2. Background Art
Pocket screwdrivers are longstanding within the hand tool art. However, even though pocket screwdrivers are well known within the art, they are not widely used among mechanics and handymen. Several deficiencies exist in the presently available pocket screwdrivers which contribute to their limited use. One major complaint is the that any screwdriver small enough to fit within a shirt pocket, which is the most convenient place to carry them, is too small to efficiently grip and therefore, applies insufficient torque to the screw head. Another complaint, is that the present day pocket screwdrivers are not versatile, in that you must carry separate screwdrivers for each type of screw i.e. both Phillips and standard slotted screws. Additionally, pocket screwdrivers have substandard sized heads which make it difficult when attending to a standard sized slot in a screw. Presently, there are available, mini sized drivers which have a plurality of miniature interchangeable bits. In addition to not being able to satisfactorily attend to standard sized slots, these miniature bits are all but irreplaceable when lost. The vast majority of hardware stores do not carry substandard sized, interchangeable tool bits, as there is no industry standard for the shank size of the driving tool for miniature bits.
STONE, U.S. Pat. No. 537,246, teaches a pocket screwdriver which has a plurality of screwdriver bits pivotally attached to a telescoping inner carriage, wherein the desired bit is selected and the carriage is inserted back into the screwdriver housing. The screwdriver of STONE has two main drawbacks, the first being that the carriage is not well suited to the addition of a Phillips head bit, and the second being, that the torque amplification means provided to the screwdriver makes the screwdriver too bulky to be carried within a shirt pocket. For instance, it is common practice for a gas station attendant to carry several pens and a tire gauge in his front shirt pocket. There is simply not room for a bulky pocket screwdriver, nor, is the additional weight of such a bulky device desirable.
In a much more recent teaching, JOHNSON, U.S. Pat. No. 3,561,510, discloses a torque amplification means extending radially outward from the shank of the screwdriver. JOHNSON does not teach, however, the use of his torque amplification means with a pocket sized screwdriver, nor, the use of interchangeable bits. One of the problems with modifying the device of JOHNSON to meet the objectives of the present invention, is that there is no place to store the torque amplification means taught by JOHNSON.
What is needed is a pocket screwdriver, which can easily be carried in a front shirt pocket, which is capable of attending to standard sized screws, whether they be of the straight slot or Phillips head variety. Accordingly, it is the object of the present invention to provide a pocket screwdriver that can be stored in a front shirt pocket and which advantageously uses standard sized interchangeable tool implements, thereby adding versatility. A further object is to provide a pocket screwdriver which includes a torque amplification means for aiding in the setting and dislodging of screws.